The date or estimated date that the allergy or intolerance resolved. This is called abatement because of the many overloaded connotations associated with resolution.

Age is generally used when the patient reports an age at which the allergy or intolerance abated. If there is no abatement element, the clinicalStatus can be used to convey whether allergy or intolerance has resolved or not. When abatementString exists, it conveys that the allergy or intolerance is abated.

Business identifiers assigned to this AllergyIntolerance by the performer or other systems which remain constant as the resource is updated and propagates from server to server.

Allows identification of the AllergyIntolerance as it is known by various participating systems and in a way that remains consistent across servers.

This is a business identifier, not a resource identifier (see discussion). It is best practice for the identifier to only appear on a single resource instance, however business practices may occasionally dictate that multiple resource instances with the same identifier can exist - possibly even with different resource types. For example, multiple Patient and a Person resource instance might share the same social insurance number.

The clinical status of the allergy or intolerance.

Refer to discussion if clincalStatus is missing data. The data type is CodeableConcept because clinicalStatus has some clinical judgment involved, such that there might need to be more specificity than the required FHIR value set allows. For example, a SNOMED coding might allow for additional specificity.

The clinical status of the allergy or intolerance.

Assertion about certainty associated with the propensity, or potential risk, of a reaction to the identified substance (including pharmaceutical product).

The data type is CodeableConcept because verificationStatus has some clinical judgment involved, such that there might need to be more specificity than the required FHIR value set allows. For example, a SNOMED coding might allow for additional specificity.

Assertion about certainty associated with a propensity, or potential risk, of a reaction to the identified substance.

Identification of the underlying physiological mechanism for the reaction risk.

Allergic (typically immune-mediated) reactions have been traditionally regarded as an indicator for potential escalation to significant future risk. Contemporary knowledge suggests that some reactions previously thought to be immune-mediated are, in fact, non-immune, but in some cases can still pose a life threatening risk. It is acknowledged that many clinicians might not be in a position to distinguish the mechanism of a particular reaction. Often the term "allergy" is used rather generically and may overlap with the use of "intolerance" - in practice the boundaries between these two concepts might not be well-defined or understood. This data element is included nevertheless, because many legacy systems have captured this attribute. Immunologic testing may provide supporting evidence for the basis of the reaction and the causative substance, but no tests are 100% sensitive or specific for sensitivity to a particular substance. If, as is commonly the case, it is unclear whether the reaction is due to an allergy or an intolerance, then the type element should be omitted from the resource.

Identification of the underlying physiological mechanism for a Reaction Risk.

Category of the identified substance.

This data element has been included because it is currently being captured in some clinical systems. This data can be derived from the substance where coding systems are used, and is effectively redundant in that situation. When searching on category, consider the implications of AllergyIntolerance resources without a category. For example, when searching on category = medication, medication allergies that don't have a category valued will not be returned. Refer to search for more information on how to search category with a :missing modifier to get allergies that don't have a category. Additionally, category should be used with caution because category can be subjective based on the sender.

Category of an identified substance associated with allergies or intolerances.

Estimate of the potential clinical harm, or seriousness, of the reaction to the identified substance.

The default criticality value for any propensity to an adverse reaction should be 'Low Risk', indicating at the very least a relative contraindication to deliberate or voluntary exposure to the substance. 'High Risk' is flagged if the clinician has identified a propensity for a more serious or potentially life-threatening reaction, such as anaphylaxis, and implies an absolute contraindication to deliberate or voluntary exposure to the substance. If this element is missing, the criticality is unknown (though it may be known elsewhere). Systems that capture a severity at the condition level are actually representing the concept of criticality whereas the severity documented at the reaction level is representing the true reaction severity. Existing systems that are capturing both condition criticality and reaction severity may use the term "severity" to represent both. Criticality is the worst it could be in the future (i.e. situation-agnostic) whereas severity is situation-dependent.

Estimate of the potential clinical harm, or seriousness, of a reaction to an identified substance.

A concept that may be defined by a formal reference to a terminology or ontology or may be provided by text.

Not all terminology uses fit this general pattern. In some cases, models should not use CodeableConcept and use Coding directly and provide their own structure for managing text, codings, translations and the relationship between elements and pre- and post-coordination.

Type of the substance/product, allergy or intolerance condition, or negation/exclusion codes for reporting no known allergies.

The patient who has the allergy or intolerance.

The encounter when the allergy or intolerance was asserted.

Estimated or actual date, date-time, or age when allergy or intolerance was identified.

The recordedDate represents when this particular AllergyIntolerance record was created in the system, which is often a system-generated date.

Individual who recorded the record and takes responsibility for its content.

The source of the information about the allergy that is recorded.

The recorder takes responsibility for the content, but can reference the source from where they got it.

Represents the date and/or time of the last known occurrence of a reaction event.

This date may be replicated by one of the Onset of Reaction dates. Where a textual representation of the date of last occurrence is required e.g. 'In Childhood, '10 years ago' the Comment element should be used.

Additional narrative about the propensity for the Adverse Reaction, not captured in other fields.

For example: including reason for flagging a seriousness of 'High Risk'; and instructions related to future exposure or administration of the substance, such as administration within an Intensive Care Unit or under corticosteroid cover. The notes should be related to an allergy or intolerance as a condition in general and not related to any particular episode of it. For episode notes and descriptions, use AllergyIntolerance.event.description and AllergyIntolerance.event.notes.

Identification of the specific substance (or pharmaceutical product) considered to be responsible for the Adverse Reaction event. Note: the substance for a specific reaction may be different from the substance identified as the cause of the risk, but it must be consistent with it. For instance, it may be a more specific substance (e.g. a brand medication) or a composite product that includes the identified substance. It must be clinically safe to only process the 'code' and ignore the 'reaction.substance'. If a receiving system is unable to confirm that AllergyIntolerance.reaction.substance falls within the semantic scope of AllergyIntolerance.code, then the receiving system should ignore AllergyIntolerance.reaction.substance.

Coding of the specific substance (or pharmaceutical product) with a terminology capable of triggering decision support should be used wherever possible. The 'code' element allows for the use of a specific substance or pharmaceutical product, or a group or class of substances. In the case of an allergy or intolerance to a class of substances, (for example, "penicillins"), the 'reaction.substance' element could be used to code the specific substance that was identified as having caused the reaction (for example, "amoxycillin"). Duplication of the value in the 'code' and 'reaction.substance' elements is acceptable when a specific substance has been recorded in 'code'.

Codes defining the type of the substance (including pharmaceutical products).

A reference to a code defined by a terminology system.

Allows for alternative encodings within a code system, and translations to other code systems.

Codes may be defined very casually in enumerations or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information.

A human language representation of the concept as seen/selected/uttered by the user who entered the data and/or which represents the intended meaning of the user.

The codes from the terminologies do not always capture the correct meaning with all the nuances of the human using them, or sometimes there is no appropriate code at all. In these cases, the text is used to capture the full meaning of the source.

Very often the text is the same as a displayName of one of the codings.

Text description about the reaction as a whole, including details of the manifestation if required.

Use the description to provide any details of a particular event of the occurred reaction such as circumstances, reaction specifics, what happened before/after. Information, related to the event, but not describing a particular care should be captured in the comment field. For example: at the age of four, the patient was given penicillin for strep throat and subsequently developed severe hives.

Record of the date and/or time of the onset of the Reaction.

Clinical assessment of the severity of the reaction event as a whole, potentially considering multiple different manifestations.

It is acknowledged that this assessment is very subjective. There may be some specific practice domains where objective scales have been applied. Objective scales can be included in this model as extensions.

Clinical assessment of the severity of a reaction event as a whole, potentially considering multiple different manifestations.

Identification of the route by which the subject was exposed to the substance.

Coding of the route of exposure with a terminology should be used wherever possible.

A coded concept describing the route or physiological path of administration of a therapeutic agent into or onto the body of a subject.

Additional text about the adverse reaction event not captured in other fields.

Use this field to record information indirectly related to a particular event and not captured in the description. For example: Clinical records are no longer available, recorded based on information provided to the patient by her mother and her mother is deceased.